Epithelioid Hemangioendothelioma of Tongue: A Rare Presentation

Hemangioendothelioma is a diverse set of proliferative and neoplastic vascular lesions with biological characteristics that fall halfway between benign hemangioma and malignant angiosarcoma. Hemangioendothelioma of the oral cavity is extremely rare and if present, it is seen on lips, gingiva, tongue, maxilla, and mandible. The following case report is about a lesion on the right ventrolateral border of the tongue of a six-year-old female patient. A Laser excision was done. Histopathology revealed the features of hemangioendothelioma. An immunohistochemical (IHC) study was done to correlate the findings with a histopathological picture and arrived at the final diagnosis of epithelioid hemangioendothelioma (EHE). The patient was followed up for two years and no recurrence was noticed.


Introduction
Weiss and Enzinger [1] were the first to define epithelioid hemangioendothelioma (EHE), a rare borderline vascular tumour characterized by endothelial cells with an epithelioid shape.These tumors have the potential for local recurrence and metastasis at a lower rate than conventional angiosarcomas [2].According to the WHO, EHE is an extremely rare, low-grade malignant vascular tumour with possible metastases that accounts for 1% of all vascular tumors [3].In the oral cavity, only a few occurrences were recorded in the literature.In terms of clinical presentation, it can resemble reactive lesions like pyogenic granulomas, chronic periodontal disease, and peripheral giant cell granulomas.Typically, patients have an ulcerated soft tissue mass that resem-bles friable granulation tissue initially [4].The hard palate is a rare intraoral location, with the submandibular area, gingiva, and alveolar mucosa being the most frequent ones.Histologically, hemangioendothelioma is distinguished by the proliferation of round, eosinophilinfiltrated endothelial cells, vacuolation of the cytoplasm, and myxohyaline stroma.Based on histological criteria, it is characterized as kaposiform, Dabskos, or epithelioid.Histologically, EHE is distinguished by the proliferation of round, eosinophil-infiltrated endothelial cells, cytoplasm vacuolation, frequent angiocentric inflammation, and myxohyaline stroma [5].We present a case of EHE that manifested as a painless enlargement on the tongue and was provisionally diagnosed as a fi- The patient was referred to a general physician for  needful systemic examination and confirmed that no abnormalities were noticed systemically as well.She was followed up for two years, and no recurrence was found.

Discussion
Mallory [6] coined the word hemangioendothelioma in 1908 to describe all the proliferations arising from endothelial cells.Endothelial cell growth surrounding a vascular lumen characterizes [7].It is classified as a vascular neoplasm having a low-tointermediate malignant potential.Its clinical and pathological characteristics place it somewhere between hemangioma and traditional angiosarcoma.EHE of the tongue was infrequently reported.There have only been ten occurrences of it on the tongue that have been documented in the literature [8].The clinical appearance of it was nonspecific, most often appearing as a benign, painless lump, while the lesion could occasionally be ulcerated [9].The present case was found to be similar in that it had ulcerated borders.The cause of EHE is unknown; however, Tanas RM et al. [10] postulated that the fusion of two distinct genes, WWTR1, and CAMTA1, is caused by the reciprocal translocation of chromosomes 1 and 3. Microscopically, it is distinguished by the proliferation of vascular epithelioid type endothelial cells with intracytoplasmic vacuoles; a few of the vacuoles may contain erythrocytes and invasion of the epithelial cells in underlying muscle tissue may or may not be present [11].Most of the time, it is discovered that the connective tissue stroma is fibro-vascular and has many vascular channels.Spindle-shaped cells may also be present in large numbers [2], which was found to be similar in the present case.According to Chi et al. [12], endothelial cells of EHE show positive expression for endothelial markers such as CD34, CD31, and factor VIII in immunohistochemistry.However, in our case, the tumour cells showed positive expression for CD31 and CD34.Histopathological and IHC results are correlated to diagnose EHE.The most effective treatment for oral EHE is broad surgical excision.Laser-assisted excision was done in the present case to minimize bleeding and enhance the comfort of the patient.Nine lesions out of 30 documented cases indicated recurrence, according to a thorough analysis of the literature.The patient was recalled for regular follow-ups due to the lesion's recurrence rate and malignant potential.The patient was followed up for two years and no recurrence was noticed (Figure 3).
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Conclusion
Based on the case and the literature reviewed, hemangioendothelioma of the oral cavity is a rare occurrence that is frequently mistaken as a benign reactive lesion, necessitating a histological diagnosis.Due to a lack of specific diagnostic criteria, the histological image remains disputed, causing diagnostic hurdles at times.In cases of oral hemangioendothelioma, prompt immunohistochemistry confirmation, followed by surgical treatment, should be required to limit the risk of local recurrence and metastasis.

Figure 1 :
Figure 1: a: Lesion on the right ventrolateral surface of the tongue, b: Immediately after excision

Figure 2 :
Figure 2: Histological examination showed nests of cells surrounding irregular vascular channels (a: H&E stain) with spindling and hyperchromatism (b: H&E stain), c: Immunohistochemical staining-Positive tumor cells cytoplasmic reaction for d: CD 31 and CD 34